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1.
IEEE Trans Image Process ; 29: 142-156, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31380761

RESUMO

Image restoration (IR) is a long-standing challenging problem in low-level image processing. It is of utmost importance to learn good image priors for pursuing visually pleasing results. In this paper, we develop a multi-channel and multi-model-based denoising autoencoder network as image prior for solving IR problem. Specifically, the network that trained on RGB-channel images is used to construct a prior at first, and then the learned prior is incorporated into single-channel grayscale IR tasks. To achieve the goal, we employ the auxiliary variable technique to integrate the higher-dimensional network-driven prior information into the iterative restoration procedure. In addition, according to the weighted aggregation idea, a multi-model strategy is put forward to enhance the network stability that favors to avoid getting trapped in local optima. Extensive experiments on image deblurring and deblocking tasks show that the proposed algorithm is efficient, robust, and yields state-of-the-art restoration quality on grayscale images.

2.
Magn Reson Med ; 83(1): 322-336, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31429993

RESUMO

PURPOSE: Although recent deep learning methodologies have shown promising results in fast MR imaging, how to explore it to learn an explicit prior and leverage it into the observation constraint is still desired. METHODS: A denoising autoencoder (DAE) network is leveraged as an explicit prior to address the highly undersampling MR image reconstruction problem. First, inspired by the observation that the prior information learned from high-dimension signals is more effective than that from the low-dimension counterpart in image restoration tasks, we train the network in a multichannel scenario and apply the learned network to single-channel image reconstruction by a variables augmentation technique. Second, because of the fact that multiple implementations of artificial noise generation in DAE favors a better underlying result, we introduce a 2-sigma rule to complement each other for improving the final reconstruction. The whole algorithm is tackled by proximal gradient descent. RESULTS: Experimental results under varying sampling trajectories and acceleration factors consistently demonstrate the superiority of the enhanced autoencoding priors, in terms of peak signal-to-noise ratio, structural similarity, and high-frequency error norm. CONCLUSION: A simple and effective way to incorporate the DAE prior into highly undersampling MR reconstruction is proposed. Once the DAE prior is obtained, it can be applied to the reconstruction tasks with different sampling trajectories and acceleration factors, and achieves superior performance in comparison with state-of-the-art methods.

3.
Chemosphere ; 238: 124528, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31425869

RESUMO

A dendrochemical study of cottonwood trees (Populus deltoides) was conducted across a childhood cancer cluster in eastern Sandusky County (Ohio, USA). The justification for this study was that no satisfactory explanation has yet been put forward, despite extensive local surveys of aerosols, groundwater, and soil. Concentrations of eight trace metals were measured by ICP-MS in microwave-digested 5-year sections of increment cores, collected during 2012 and 2013. To determine whether the onset of the first cancer cases could be connected to an emergence of any of these contaminants, cores spanning the period 1970-2009 were taken from 51 trees of similar age, inside the cluster and in a control area to the west. The abundance of metals in cottonwood tree annual rings served as a proxy for their long-term, low-level accumulation from the same sources whereby exposure of the children may have occurred. A spatial analysis of cumulative metal burdens (lifetime accumulation in the tree) was performed to search for significant 'hotspots', employing a scan statistic with a mask of variable radius and center. For Cd, Cr, and Ni, circular hotspots were found that nearly coincide with the cancer cluster and are similar in size. No hotspots were found for Co, Cu, and Pb, while As and V were largely below method detection limits. Whereas our results do not implicate exposure to metals as a causative factor, we conclude that, after 1970, cottonwood trees have accumulated more Cd, Cr, and Ni, inside the childhood cancer cluster than elsewhere in Sandusky County.

4.
J Dairy Sci ; 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31704007

RESUMO

Specific DNA mutations underlying several genetic defects associated with embryo loss or reduced calf survivability have been identified in dairy cattle, and a convenient and cost-effective platform is required for their routine screening. We developed Kompetitive allele-specific PCR (KASP) assays for discrimination of the wild-type alleles from the associated defective alleles at each of 8 common genetic defects in Holstein cattle, involving 5 SNP [HH1, HH3, HH4, bovine leukocyte adhesion deficiency (BLAD), and complex vertebral malformation (CVM)] and 3 insertion or deletion mutations [HH5, haplotype for cholesterol deficiency (HCD), and brachyspina (BS)]. A total of 390 cows from a Chinese Holstein herd were genotyped and the carriers identified at 7 of these 8 loci (except HH4), with the highest carrier frequencies found for CVM (10.5%) and HH1 (10.0%), followed by HH3 (2.6%), BS (2.1%), HCD (1.3%), HH5 (0.8%), and BLAD (0.5%). Surprisingly, 102 cows (26.2%) carried at least 1 of the 7 defective alleles. Our results demonstrate that these KASP assays are simple, rapid, and reliable for the detection of multiple genetic defects. The high carrier frequency of these genetic defects indicates an urgent need for routine molecular testing to eliminate the deleterious alleles from Chinese Holstein cattle.

5.
J Nat Prod ; 82(11): 3056-3064, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31668072

RESUMO

Three new germacrane sesquiterpenoid-type alkaloids with an unusual Δ8-7,12-lactam moiety, glechomanamides A-C (1-3), and two pairs of 7,12-hemiketal sesquiterpenoid epimers (4a/b, 5a/b) were isolated from Salvia scapiformis. Their structures were elucidated by spectroscopic methods including HRESIMS, IR, UV, and 1D and 2D NMR and also confirmed by single-crystal X-ray diffraction analysis. The chemical transformation of compounds 1-5 in a solution environment was analyzed by 2D NMR spectroscopy. The aza acetallactams (1-3) were stable in organic solvent, while single crystals of the hemiacetal esters (4a/b, 5a/b) underwent a tautomeric equilibrium after being dissolved. Single crystals of 4a, 4b, and 5a were obtained for the first time as their naturally occurring forms. Glechomanamide B (2) exhibited antiangiogenic activity by suppression of vascular endothelial growth factor (VEGF)-induced tube formation through modulation of VEGF receptor 2 (VEGFR2)-mediated signaling pathways in human umbilical vascular endothelial cells (HUVECs). In addition, compound 2 also showed the significant suppression of mRNA expression associated with glycolysis and angiogenesis biomarkers in high glucose (30 mM)-induced HUVECs. These findings suggest that compound 2 might be a potential lead compound candidate for the management of diabetic retinopathy.

6.
Sci Total Environ ; : 135586, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31767336

RESUMO

The pharmaceutical industry produces large volumes of low C/N ratio wastewater that is difficult to treat. In this study, we isolated Achromobacter sp. JL9 with high efficiency for sulfamethoxazole degradation and nitrogen conversion in low C/N ratio pharmaceutical wastewater. The SMX biodegradation and nitrogen removal ratio were 92.4% (nitrate-N), 86.7% (ammonia-N), 89.4% (total nitrogen), and 90.4% (SMX). The reaction kinetics and reaction rate constant were C/N ratio-, SMX concentration-, and dissolved oxygen concentration-dependent, and the highest reaction rate constant for SMX biodegradation was 0.0384 min-1. Gaseous compounds analysis and Nap gene amplification analysis by gas chromatography (GC) and polymerase chain reaction (PCR), respectively, showed N2 as an end product during nitrogen conversion. Moreover, toxicity assays were conducted by the inhibition percentage (PI) and agar well diffusion methods. The toxicity of the medium gradually decreased, falling within the nontoxic range after 96 h. The present study showed that biological technologies could be an effective, economical, and environmentally friendly remediation against pharmaceutical pollutants.

7.
Org Lett ; 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31746212

RESUMO

Catalytic enantioselective chemical reactions involving highly reactive radical species remain largely unexplored. We report herein for the first time a novel enantioselective radical ring-opening cyanation of redox-active oxime esters by dual photoreodox and copper catalysis. This mild protocol shows good functional group tolerance and broad substrate scope, producing a wide range of optically active alkyl dinitriles with high yields and excellent enantioselectivities, which are difficult to access traditionally.

8.
Int J Oncol ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31746425

RESUMO

Epithelial ovarian cancer is aggressive and lacks effective prognostic indicators or therapeutic targets. In the present study, using immunohistochemistry and bioinformatics analysis on ovarian cancer tissue data from The Obstetrics and Gynecology Hospital of Fudan University and The Cancer Genome Atlas database, it was identified that FXYD domain­containing ion transport regulator 5 (FXYD5) expression was upregulated in the SKOV3­IP cell line compared with its parental cell line, SKOV3, and in ovarian cancer tissues compared with in normal tissues. In addition, FXYD5 upregulation was predictive of poor patient survival. Furthermore, through various in vitro (Transwell assay, clonogenic assay and western blot analysis) and in vivo (nude mouse model) experiments, it was demonstrated that FXYD5 promoted the metastasis of ovarian cancer cells. Mechanistically, RNA sequencing, western blot analysis, a luciferase reporter assay and chromatin immunoprecipitation were performed to reveal that FXYD5 dispersed the SMAD7­SMAD specific E3 ubiquitin protein ligase 2­TGF­ß receptor 1 (TßR1) complex, deubiquitinated and stabilized TßR1, and subsequently enhanced transforming growth factor­ß (TGF­ß) signaling and sustained TGF­ß­driven epithelial­mesenchymal transition (EMT). The TGF­ß­activated SMAD3/SMAD4 complex was in turn directly recruited to the FXYD5 promoter region, interacted with specific SMAD­binding elements, and then promoted FXYD5 transcription. In brief, FXYD5 positively regulated TGF­ß/SMADs signaling activities, which in turn induced FXYD5 expression, creating a positive feedback loop to drive EMT in the process of ovarian cancer progression. Collectively, the findings of the present study suggested a mechanism through which FXYD5 serves a critical role in the constitutive activation of the TGF­ß/SMADs signaling pathways in ovarian cancer, and provided a promising therapeutic target for human ovarian cancer.

9.
Zootaxa ; 4629(2): zootaxa.4629.2.5, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31712522

RESUMO

A new winter stonefly species of the genus Capnia Pictet, 1841, Capnia s.l. bilobata sp. nov. is described and illustrated from Shaanxi Province of northwestern China. The new species is distinguished from all currently known Capnia s.l. by the male and female genitalic characters. The falciform projection on male tergum 9 and the unique-shaped female subgenital plate separate the new taxon from other congeners.


Assuntos
Insetos , Lepidópteros , Distribuição Animal , Animais , China , Feminino , Masculino , Neópteros
10.
Zootaxa ; 4619(3): zootaxa.4619.3.8, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31716294

RESUMO

A new species of the peltoperlid genus Microperla Chu, 1928, Microperla qinlinga Chen, sp. nov. from Shaanxi Province of northwestern China is described and illustrated. The new species is characterized by the widely rounded ventral lobe in males and the extremely large and bilobed subgenital plate in female. In addition, the taxonomic history and current status of the genus Microperla is reviewed.


Assuntos
Insetos , Distribuição Animal , Animais , China , Feminino , Masculino , Neópteros
11.
Zootaxa ; 4651(2): zootaxa.4651.2.11, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31716917

RESUMO

A new species of the perlodid genus Isoperla Banks, 1906, Isoperla qinlinga Chen, sp. nov. from Shaanxi Province of northwestern China is described. The new species is characterized by the mostly dark head and pronotum, the poorly developed vesicle, the modified ventral and dorsal aedeagal lobes, and the slightly developed, rounded subgenital plate of the female. Comments are provided on the known species of Isoperla of China.


Assuntos
Insetos , Animais , China , Feminino , Neópteros
12.
Magn Reson Med ; 2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31762102

RESUMO

PURPOSE: To develop and evaluate a fast imaging method based on signal-compensated low-rank plus sparse matrix decomposition to accelerate data acquisition for biexponential brain T1ρ mapping (Bio-SCOPE). METHODS: Two novel strategies were proposed to improve reconstruction performance. A variable-rate undersampling scheme was used with a varied acceleration factor for each k-space along the spin-lock time direction, and a modified nonlinear thresholding scheme combined with a feature descriptor was used for Bio-SCOPE reconstruction. In vivo brain T1ρ mappings were acquired from 4 volunteers. The fully sampled k-space data acquired from 3 volunteers were retrospectively undersampled by net acceleration rates (R) of 4.6 and 6.1. Reference values were obtained from the fully sampled data. The agreement between the accelerated T1ρ measurements and reference values was assessed with Bland-Altman analyses. Prospectively undersampled data with R = 4.6 and R = 6.1 were acquired from 1 volunteer. RESULTS: T1ρ -weighted images were successfully reconstructed using Bio-SCOPE for R = 4.6 and 6.1 with signal-to-noise ratio variations <1 dB and normalized root mean square errors <4%. Accelerated and reference T1ρ measurements were in good agreement for R = 4.6 (T1ρ s : 18.6651 ± 1.7786 ms; T1ρ l : 88.9603 ± 1.7331 ms) and R = 6.1 (T1ρ s : 17.8403 ± 3.3302 ms; T1ρ l : 88.0275 ± 4.9606 ms) in the Bland-Altman analyses. T1ρ parameter maps from prospectively undersampled data also show reasonable image quality using the Bio-SCOPE method. CONCLUSION: Bio-SCOPE achieves a high net acceleration rate for biexponential T1ρ mapping and improves reconstruction quality by using a variable-rate undersampling data acquisition scheme and a modified soft-thresholding algorithm in image reconstruction.

13.
Fitoterapia ; 139: 104408, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31698058

RESUMO

One new pseudoguaianolide (1), one new megastigmane (6), and one new ent-abietane diterpene (9), together with seven known compounds (2-5, 7, 8, and 10) were isolated from the aerial parts of Euphorbia thymifolia. The structures of the new compounds and their relative configurations were determined by spectroscopic data analysis. The absolute configurations of compounds 1, 6, and 9 were determined by single-crystal X-ray crystallographic analysis, modified Mosher's method and calculated ECD experiment, respectively. All compounds were tested for their inhibitory effects against LPS-induced NO production in BV-2 microglial cells, and pseudoguaianolides (1-5) showed significant activity with IC50 values of 0.41-15.32 µM.

14.
Sensors (Basel) ; 19(23)2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31771250

RESUMO

Foreground detection is an important theme in video surveillance. Conventional background modeling approaches build sophisticated temporal statistical model to detect foreground based on low-level features, while modern semantic/instance segmentation approaches generate high-level foreground annotation, but ignore the temporal relevance among consecutive frames. In this paper, we propose a Spatio-Temporal Attention Model (STAM) for cross-scene foreground detection. To fill the semantic gap between low and high level features, appearance and optical flow features are synthesized by attention modules via the feature learning procedure. Experimental results on CDnet 2014 benchmarks validate it and outperformed many state-of-the-art methods in seven evaluation metrics. With the attention modules and optical flow, its F-measure increased 9 % and 6 % respectively. The model without any tuning showed its cross-scene generalization on Wallflower and PETS datasets. The processing speed was 10.8 fps with the frame size 256 by 256.

15.
Plant Physiol ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31772076

RESUMO

Malate accumulation in the vacuole largely determines apple (Malus domestica) fruit acidity, and low fruit acidity is strongly associated with truncation of Ma1, an ortholog of ALUMINUM-ACTIVATED MALATE TRANSPORTER9 (ALMT9) in Arabidopsis (Arabidopsis thaliana). A mutation at base 1455 in the open reading frame of Ma1 leads to a premature stop codon that truncates the protein by 84 amino acids at its C-terminal. Here, we report both the full length protein, Ma1, and its naturally occurring truncated protein, ma1, localize to the tonoplast; when expressed in Xenopus laevis oocytes and Nicotiana benthamiana cells, Ma1 mediates a malate-dependent inward-rectifying current, whereas the ma1-mediated transmembrane current is much weaker, indicating ma1 has significantly lower malate transport activity than Ma1. RNAi suppression of Ma1 expression in 'McIntosh' apple leaves, 'Empire' apple fruit, and 'Orin' apple calli results in a significant decrease in malate level. Genotyping and phenotyping of 186 apple accessions from a diverse genetic background of 17 Malus species combined with the functional analyses described above indicate Ma1 plays a key role in determining fruit acidity and the truncation of Ma1 to ma1 is genetically responsible for low fruit acidity in apple. Furthermore, we identified a C-terminal domain conserved in all tonoplast-localized ALMTs essential for Ma1 function; protein truncations into this conserved domain significantly lowers Ma1 transport activity. We conclude the truncation of Ma1 to ma1 reduces its malate transport function by removing a conserved C-terminal domain, leading to low fruit acidity in apple.

16.
Magn Reson Med ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31658397

RESUMO

PURPOSE: To propose a parameter optimization framework on wave gradients of Wave-CAIPI imaging for decreasing g-factor penalty and reducing reconstruction artifacts. THEORY AND METHODS: The influences of parameters on g-factor are theoretically analyzed. The average g-factor is chosen as a metric for parameter optimization, and then a fast calculation method is proposed to approximately and ultra-fast calculate the average g-factor. Based on this, a set of points in the function of the average g-factor with respect to the wave gradient parameters is calculated, and the optimal wave gradient parameters are found according to these points. RESULTS: In vivo human brain experiments were performed on 3T MR scanners for the comparison experiments. The results show that the proposed parameter optimization framework is able to efficiently obtain optimal wave gradient parameters, which can achieve decreased g-factor penalty and less artifacts of reconstructions than the empirical parameters. CONCLUSION: The proposed parameter optimization framework is computationally efficient and can optimize the wave gradient parameters of Wave-CAIPI imaging for better image quality than before.

17.
Zhongguo Zhong Yao Za Zhi ; 44(17): 3738-3744, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31602947

RESUMO

Seventeen compounds were isolated from the 95% ethanol extract of the stems and leaves of Sapium discolor by using various chromatographic techniques,including silica gel,Sephadex LH-20,MCI,ODS,and semi-preparative HPLC. Their structures were elucidated as sapiumin F( 1),kadsulignan C( 2),ciwujiatone( 3),ethylbrevifolin carboxylate( 4),7-hydroxy-8-methoxycoumarin( 5),fraxetin( 6),fraxidin( 7),isofraxidin( 8),6,7,8-trimethoxycoumarin( 9),5,6,7,8-tetramethoxycoumarin( 10),8-hydroxy-5,6,7-trimethoxycoumarin( 11),3,3'-di-O-methylellagic acid( 12),3,3',4'-tri-O-methylellagic acid( 13),3'-methoxyellagic acid 4'-O-α-rhamnopyranoside( 14),4,5-didehydro-chebulic acid triethyl ester( 15),ent-kaurane-3-oxo-16α,17-diol( 16),and abscisic acid( 17) by spectroscopic data. Compound 1 is a new compound. Except for compounds 4,11,and 13,the remaining compounds were isolated from this plant for the first time. All the isolates were evaluated for their in vitro antineuroinflammatory activities,and the results showed that compounds 6 and 15 significantly inhibited nitric oxide production in lipopolysaccharide-induced BV-2 microglial cells,with IC50 values of 6. 06 and 6. 05 µmol·L-1,respectively.


Assuntos
Compostos Fitoquímicos/análise , Folhas de Planta/química , Caules de Planta/química , Sapium/química , Animais , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Camundongos
18.
Org Lett ; 21(21): 8783-8788, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31625757

RESUMO

A visible-light-driven, perfluoroalkyl radical-mediated strategy for in situ formation of aza-o-QMs from readily available precursors is reported. Combination of this method with a Brønsted base thus enables an efficient and highly diastereoselective HDA reaction between such photogenerated aza-o-QMs and π-electron-poor systems, aldehydes, providing high yielding and rapid access to valuable, diversely substituted dihydrobenzoxazines. DFT calculation elucidated the origins of stereochemistry of the products and disclosed the concerted property of the process.

19.
Glob Chang Biol ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31580516

RESUMO

Production and consumption of nitrous oxide (N2 O), methane (CH4 ), and carbon dioxide (CO2 ) are affected by complex interactions of temperature, moisture, and substrate supply, which are further complicated by spatial heterogeneity of the soil matrix. This microsite heterogeneity is often invoked to explain non-normal distributions of greenhouse gas (GHG) fluxes, also known as hot spots and hot moments. To advance numerical simulation of these belowground processes, we expanded the Dual Arrhenius and Michaelis-Menten model, to apply it consistently for all three GHGs with respect to the biophysical processes of production, consumption, and diffusion within the soil, including the contrasting effects of oxygen (O2 ) as substrate or inhibitor for each process. High-frequency chamber-based measurements of all three GHGs at the Howland Forest (ME, USA) were used to parameterize the model using a multiple constraint approach. The area under a soil chamber is partitioned according to a bivariate log-normal probability distribution function (PDF) of carbon and water content across a range of microsites, which leads to a PDF of heterotrophic respiration and O2 consumption among microsites. Linking microsite consumption of O2 with a diffusion model generates a broad range of microsite concentrations of O2 , which then determines the PDF of microsites that produce or consume CH4 and N2 O, such that a range of microsites occurs with both positive and negative signs for net CH4 and N2 O flux. Results demonstrate that it is numerically feasible for microsites of N2 O reduction and CH4 oxidation to co-occur under a single chamber, thus explaining occasional measurement of simultaneous uptake of both gases. Simultaneous simulation of all three GHGs in a parsimonious modeling framework is challenging, but it increases confidence that agreement between simulations and measurements is based on skillful numerical representation of processes across a heterogeneous environment.

20.
Bioresour Technol ; 293: 122061, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520862

RESUMO

This study investigated sulfamethoxazole (SMX) biodegradation and nitrogen conversion by Achromobacter sp. JL9 using different carbon and nitrogen sources. Results showed that SMX and sodium acetate could be co-metabolized as carbon sources for bacterial growth and nitrogen conversion with highest removal efficiencies of 82.44%, 80.2%, and 79.45% for NH4+-N, NO3--N, and SMX, respectively. Strain JL9 was able to utilize SMX as its sole nitrogen source for growth, with an SMX biodegradation efficiency of 63.10%. In addition, carbon and nitrogen balance analyses showed that approximately 35.31% and 63.22% of carbon and nitrogen, respectively, were lost as gaseous products. Finally, medium toxicity gradually decreased during the carbon and nitrogen dependence experiments. This study, thus, suggests that carbon and nitrogen play vital roles in SMX biodegradation and biotoxicity reduction.


Assuntos
Achromobacter , Sulfametoxazol , Biodegradação Ambiental , Carbono , Nitrogênio
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